Charles Ellicott Commentary Amos 8:5

"saying, When will the new moon be gone, that we may sell grain? and the sabbath, that we may set forth wheat, making the ephah small, and the shekel great, and dealing falsely with balances of deceit;" — Amos 8:5 (ASV)

When ... gone.— They desired that the festivals of the New Moon and Sabbath would be over, so that they might not only return to their secular employments but also pursue their search for ill-gotten gains—a proof that these festivals were observed in the northern nation, even if they were disliked.

Set forth wheat.— The original signifies the opening of the sacks, or granaries, where the wheat was stored. The greedy mercantile class is referred to. The ephah, which was a dry measure (equal to three English pecks), was “made small,” so that a smaller quantity could be sold. The shekel was the weight against which the precious metal was weighed. If this were fraudulently augmented, more of the gold or silver than was due was demanded for the impoverished ephah.

Falsifying the balances ...—More accurately, falsifying the deceitful balances, so that the very symbol of justice became the implement for committing injustice. This is frequently condemned in the Law and Prophets (Leviticus 19:35–36; Deuteronomy 25:15; Proverbs 11:1; Micah 6:11).